The present invention relates to a method for processing a series of signals, particularly radio signals exhibiting a same interval of a low frequency between adjacent signals, especially radiofrequency signals, of a radionavigation system such as the RANA system, to allow, by using the phases of the signals received, the location of a receiver set, and a receiver for carrying out the said method.
The conventional methods consist in converting the radiofrequency signals into signals exhibiting a lower frequency, by means of mixer means, in separating the various signals of lower frequency in filters so tuned as to obtain at the output of each of the filters a signal isolated from the adjacent signals. These known methods suffer from the major drawback that the filters must display sharp selectivity characteristics because of the proximity of the frequencies to be separated. The phase shift inherent in the filtering may result in random errors in the phase-shift measurements which follow. This technique must therefore generally be completed by so-called self-testing measurements for which it is necessary to locally generate standard signals which are momentarily substituted for the reception signals. Furthermore, it is observed that these known methods require the use of as many filters as there are signals to be processed, since, as is well known, at least three filters are necessary to make two phase difference measurements. There results therefrom a complex and costly structure of the receivers.